Improvement in safety-valves for steam-boilers



E.r. STEELE. Safety-Valves for Steam-Bailars.

No.147292I Patentedlr'e b 1 0 l 8 7 4.

NIT g1.;

A'rENfr OFFICE.

ELIJAH F. STEELE, OF WALLINGFORD, CONNEGTIGT.

Specification forming part of Letters Patent No. 147,292, dated February l0, 1874 application filed January 9, 1874.

for Steam-Boilers, of which the following is a `specification The object of this invention is to furnish a valve which shall be sensitive to slight changes in the pressure of the steam, and of compact form, which causes it to be very suitable for use upon locomotive-boilers or thoseot portay ble engines. The invention consists in an arrangement of two valves connected by a stem or rod, a spiral spring, a sleeve incasing the spring and part of the valve-stem, and an adating together as hereinafter fully described.

The drawing is a-sectional view of the invention, with the valves open for the escape ot' steam.

A represents the case, forming a hollow globe, with suitable chambers for the passage ofthe steam. vB B are the valves, nearly equal in size, the surface of the valve B being so much increased as to give it suiiicient lifting power, under ordinary pressures, to lift both valves with'the stem and its connections. C C are the valve-seats, and D is the valve stein or rod, around the upper part of which is coiled the spiral spring E, it is also provided, at its upper end, with a scale and ring, K, by which the valve may be raised `when desired. The cap or nut F is screwed upon the sleeve G, and is used to regulate the tension of the spring, also serving as a stop for the valves at G. This sleeve, containing; the spiral spring and valve-stem, forms part of a plate, L, which is secured to the case A by screw-bolts. H is the opening to which the steam-pipe leading from the boiler is attached. I is the opening for a pipe leading to the engine, and J is the escape-pipe. valve-stem form an index for setting the valve to any desired pressure by screwing down the adjustable cap F until its upper surface is in line with the figures 0n the stem, which indicates the pressure required. The arrows indi cate the course of the steam in passing through the valve. y

By means of this arrangement, I am enabled to dispense with the levers and great weights, usual in ordinary safety-valves, to insure more speedy relief of the pressure upon the boiler, to adjust the valve easily so as to discharge at a given pressure, and to diminish the danger of the valves being broken or stuck down by i any sudden and violent closing. instable nut or cap, all constructed and opery In operation, it willl be seen, the valve B being larger than B `the valves are raised and opened by the excess of pressure of the steam upon B over that upon B. The spiral spring E acts with B to keep thevalve closed. This spring is adjusted by the nut F, accord` ing to the index on the valve-stem, to resist any required pressure, so that the valves open when the pressure upon the valve B exceeds the resistance of the spring and valve B.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- The combination of the case A, provided with the openings H I J, and the plate L, provided with the sleeve G, the valves B B', the

valve-stem I), cap F, and spring E, substan-4 tially as and for the purpose hereinbei'ore set fort-h.

In testimony that I claim the foregoing, I have hereunto set my hand this 26th day of December, 1873.

ELIJAH F. STEELE.

J UDAH FRrsBIE, HENRY E. PARDU.

The scale and iigures on the 

